Livestock produce a large amount of manure. The high nitrogen content of the manure makes it useful as a fertilizer on agricultural fields. While manure is continually produced, it is only needed as fertilizer during certain times of the year. During the times it is being produced and not yet needed, it must be stored. It is also desirable to break down the manure prior to application as a fertilizer. One method of storing and breaking down livestock manure is a manure lagoon. Manure lagoons are sloped, fluid impermeable pits fifteen to thirty-five feet deep and may be several hundred feet across.
Manure from a livestock operation is pumped into a lagoon where anaerobic bacteria digest, liquefy, and convert a portion of the manure to carbon dioxide, methane, ammonia and hydrogen sulfide. The resulting supernatant contains nitrogen and calcium. The resulting solids form a sludge that rests on the bottom of the manure lagoon. The sludge is made up of several biodegradable organic solids, including lignin and cellulose. The sludge also contains high concentrations of phosphorous. After anaerobic bacteria breaks down the manure, the manure is pumped from the lagoon to a tank for transport and then applied to an agricultural field.
To prevent an undesirable buildup of sludge at the bottom of the lagoon, it is known in the art to place an agitator within the lagoon to create a slurry by moving solids in sludge into suspension within the supernatant. Prior art methods of agitating the manure include attaching a shaft with a propeller or auger to the power takeoff of a tractor or other farm vehicle resting on the shore. The rotating propeller or auger forces the supernatant down into the sludge, causing the solids within the sludge to move upward into suspension within the supernatant. While this method does place some solids into suspension, the method has several drawbacks. One drawback is that the propeller or auger forces sludge up from the bottom of the lagoon in only a narrow area. While the propeller or auger may be moved to provide a more even distribution of solids within the supernatant, moving the propeller or auger is time consuming.
Alternatively, the propeller or auger may be rotated at an increased speed to move more sludge to move into suspension. One drawback associated with increasing the speed of rotation of the propeller or auger is the increased risk to the bottom of the lagoon. If the speed of the rotation of the propeller or auger is increased too much, the bottom of the lagoon may be damaged, allowing the manure to leak into the ground water. Yet another drawback associated with the prior art is mixing sludge at the center of the lagoon. Prior art agitators are typically operated from shore. Even with long agitators it is difficult to mix sludge at the center of the lagoon, which leads to a buildup of sludge at the center of the lagoon. It would, therefore, be desirable to provide deep agitation at the center of the lagoon, to more thoroughly suspend the sludge solids within the supernatant.
It is also known in the art to provide a large vehicle that may be lowered into the lagoon. The vehicle may be equipped with a fluid intake, a pump and a fluid output to draw supernatant into the pump and force the supernatant at high speed downward toward the sludge. The vehicle is typically moved with cables by operators on the shore.
One drawback associated with such devices is that these devices are not easily maneuverable. Another drawback associated with such prior art devices is the difficulty associated with controlling such devices. Often elaborate systems of wires and securement posts must be erected near the shores of the manure lagoon to provide a guide for the vehicle to move during the agitation process. As the vehicle typically makes several passes across the lagoon, several guide wires and posts must be set up to accommodate multiple passes. The devices can be difficult to steer during passes across the lagoon.
It would, therefore, be desirable to provide a vehicle which floats on the manure pond and which is maneuverable. It would also be desirable to provide the vehicle with multiple outlet nozzles to direct the fluid downward into the lagoon a sufficient distance to agitate the solids in the bottom of the lagoon into suspension and create vortices within the lagoon to assist in carrying solids within the sludge into suspension in the supernatant. It would additionally be desirable to direct the nozzles to create vortices that mix the solids of the sludge into suspension with the supernatant, while minimizing the amount of unpleasant smelling hydrogen sulfide rising to the surface and escaping into the air.
It would further be desirable to provide a floating vehicle for the mixing of sludge solids into suspension with the supernatant that may be quickly and readily transported to a manure lagoon, launched into the lagoon, used to suspend sludge solids into suspension with the supernatant, and removed from the lagoon onto a trailer. It would also be desirable to provide a floating vehicle configured to the standard, height, weight and width restrictions associated with highway travel. Additionally, it would be desirable to provide a floating manure agitation vehicle that may be remotely controlled and guided to specific portions of the lagoon to move solids of the sludge into suspension with the supernatant as desired.
The difficulties encountered in the prior art discussed hereinabove are substantially eliminated by the present invention.